1. Field of the Invention
The present invention relates to a dispersion and skimming device for use as a mixing system. More particularly, the invention relates to a system for mixing substances having different specific gravities. Mixtures of such substances pose difficulties due to the tendency of the substance having a lower specific gravity to separate and float on top of the mixture.
2. Related Art
Attempts have been made at addressing the difficulty of mixing materials having different specific gravities. The tendency of materials having different specific gravities to separate, whereby the low specific gravity material floats on top of the material having a higher specific gravity, requires that mixing be thorough and continuous.
Related mixing devices include U.S. Pat. No. 2,342,559 to Sebald et al. for a Mixing Device for Water Treating Apparatus; U.S. Pat. No. 4,084,796 to Krehbiel for a Liquid Mixing Device; U.S. Pat. No. 4,170,420 to Underwood for a Fluid Mixing System; U.S. Pat. No. 4,660,988 to Hara et al. for a Stirring Device for Liquid Material; and U.S. Pat. No. 4,986,293 to Schertenleib for a Cleaning System.
Previous mixing devices generally teach an inlet wherein fluid is drawn through tubing to a circulation means. The fluid is then recirculated into a mixing device through a discharge means. Previously used inlet means include a pivoting inlet pipe, wherein the inlet can be positioned at various heights, and a tube positioned inside a tank that has an elongated spiral slot, wherein the tube draws in liquids at various depths in the tank. Other inlet means include a suction conduit having a plurality of inductor inlets.
The material drawn into the inlet tube of the mixing system is typically recirculated and discharged back into the mixing tank by various means. Such means include returning the fluid through the bottom of the tank where the fluid passes through a diffuser. Other means include introducing liquid back into the tank through a discharge port, introducing fluid into an injector conduit, and withdrawing liquid material from a stirring tank and returning the material through a nozzle pipe through a plurality of nozzle holes.
Insofar as Applicant is aware, no previous device has a combination dispersion and skimming device wherein a tank includes a telescoping tube having an adjustable height and a skimmer positioned on the end of the tube. Additionally, Applicant is unaware of any previous device that returns skimmed matter through a dispersion tube having a series of openings that allow the matter to be dispersed throughout the entire mixture or only a portion of the mixture.
Applicant is also unaware of any prior art device that teaches the use of an adjustable intake tube that is impervious to damaging forces resulting from the circulation of fluids. Such forces are particularly troublesome in the case of heavy fluids such as asphalt.
Consequently, it is desirable to provide a combination dispersion and skimming device and method wherein the device has an adjustable intake tube so that floating substances, having a lower specific gravity, may be skimmed from the surface and dispersed throughout the mixture.
Further, it is desirable to provide an adjustable intake tube wherein the tube may be located centrally within the tank, thereby minimizing detrimental forces acting on the intake tube due to circulation of the mixture within the tank.
Additionally, it is desirable to utilize a dispersion tube so that material of lower specific gravity may be reinjected into the tank at locations throughout different areas of the tank, thereby effecting a more thorough mixing of materials of high and low specific gravities.